Pyloric anchors and methods for intestinal bypass sleeves

ABSTRACT

A gastrointestinal device for implanting within a patient&#39;s gastrointestinal tract, the device having a central axis and a first expandable portion comprising a hollow tubular braided structure of wire and having a first cylinder extending parallel to the central axis, the first cylinder having a length and a first face; a neck portion extending from the first face of the first expandable portion parallel to the central axis, the neck portion having a first end, a second end, a wall extending between the first end and second end, and a diameter sized to fit within a pylorus; and a second expandable portion comprising a hollow tubular braided structure of wire and having a second cylinder extending parallel to the central axis, the second cylinder having a second face located at the proximal end of the second cylinder and oriented transverse to the central axis.

TECHNICAL FIELD

The instant disclosure relates generally to implants placed withingastrointestinal systems, including the esophagus, the stomach and theintestines. More particularly, it relates to devices and methods forimplant systems having components implantable and removable usingendoscopic techniques for treatment of obesity, diabetes, reflux,gastroparesis and other gastrointestinal conditions.

BACKGROUND

Bariatric surgery procedures, such as sleeve gastrectomy, the Roux-en-Ygastric bypass (RYGB) and the bileo-pancreatic diversion (BPD), modifyfood intake and/or absorption within the gastrointestinal system toeffect weight loss in obese patients. These procedures affect metabolicprocesses within the gastrointestinal system, by either short circuitingcertain natural pathways or creating different interactions between theconsumed food, the digestive tract, its secretions and theneuro-hormonal system regulating food intake and metabolism. In the lastfew years there has been a growing clinical consensus that obesepatients who undergo bariatric surgery see a remarkable resolution oftheir type-2 Diabetes Mellitus (T2DM) soon after the procedure. Theremarkable resolution of diabetes after RYGB and BPD typically occurstoo fast to be accounted for by weight loss alone, suggesting there maybe a direct impact on glucose homeostasis. The mechanism of thisresolution of T2DM is not well understood, and it is quite likely thatmultiple mechanisms are involved.

One of the drawbacks of bariatric surgical procedures is that theyrequire fairly invasive surgery with potentially serious complicationsand long patient recovery periods. In recent years, there has beenincreased effort to develop minimally invasive procedures to mimic theeffects of bariatric surgery. One such procedure involves the use ofgastrointestinal implants that modify transport and absorption of foodand organ secretions. For example, U.S. Pat. No. 7,476,256 describes animplant having a tubular sleeve with anchoring barbs, which offer thephysician limited flexibility and are not readily removable orreplaceable. Moreover, stents with active fixation means, such as barbsthat deeply penetrate into surrounding tissue, may potentially causetissue necrosis and erosion of the implants through the tissue, whichcan lead to complications, such as bacterial infection of the mucosaltissue or systemic infection. Also, due to the intermittent peristalticmotion within the digestive tract, implants such as stents have atendency to migrate.

Gastroparesis is a chronic, symptomatic disorder of the stomach that ischaracterized by delayed gastric emptying in the absence of mechanicalobstruction. The cause of gastroparesis is unknown, but it may be causedby a disruption of nerve signals to the intestine. The three most commonetiologies are diabetes mellitus, idiopathic, and postsurgical. Othercauses include medication, Parkinson's disease, collagen vasculardisorders, thyroid dysfunction, liver disease, chronic renalinsufficiency, and intestinal pseudo-obstruction. The prevalence ofdiabetic gastroparesis (DGP) appears to be higher in women than in men,for unknown reasons.

Diabetic gastroparesis affects about 40% of patients with type 1diabetes and up to 30% of patients with type 2 diabetes and especiallyimpacts those with long-standing disease. Both symptomatic andasymptomatic DGP seem to be associated with poor glycemic control bycausing a mismatch between the action of insulin (or an oralhypoglycemic drug) and the absorption of nutrients. Treatment ofgastroparesis depends on the severity of the symptoms.

SUMMARY

Disclosed herein is a gastrointestinal implant for use within a pylorus,a duodenal bulb, and a duodenum of a patient, the implant having anexpanded configuration and a contracted configuration and comprising: aproximal portion comprising a hollow tubular braided structure of wireshaped to form a cylinder having a proximal end, a distal end, and aproximal wall extending radially inward from the proximal portion distalend, wherein the proximal wall has an outer circumference and an innercircumference and is configured with a first bias such that the innercircumference is located closer to the proximal portion proximal endthan the proximal portion outer circumference; a neck portion comprisinga cylinder having a proximal end and a distal end and extending distallyfrom the inner circumference of the proximal portion, the neck portionhaving a length greater than a width of a pylorus; a distal portioncomprising a hollow tubular braided structure of wire shaped to form acylinder extending distally from the neck portion and having a proximalend, a distal end, and a distal wall extending radially inward from thedistal portion proximal end, wherein the distal wall has an outercircumference and an inner circumference and is configured with a secondbias such that the inner circumference is located closer to the distalportion distal end than the distal portion outer circumference; and astructural element coupled to the distal portion and configured toresist circumferential compression.

Also disclosed herein is a gastrointestinal device for implanting withina pylorus, a duodenal bulb, and a duodenum of a patient'sgastrointestinal tract, the device having a central axis and comprisinga first expandable portion comprising a hollow tubular braided structureof wire and having a first cylinder extending parallel to the centralaxis, the first cylinder having a proximal end, a distal end, and alength and a first face located at the distal end of the first cylinderand oriented transverse to the central axis; a neck portion extendingfrom the first face of the first expandable portion parallel to thecentral axis, the neck portion having a first end, a second end, a wallextending between the first end and second end, and a diameter sized tofit within a pylorus; and a second expandable portion comprising ahollow tubular braided structure of wire and having a second cylinderextending parallel to the central axis, the second cylinder having aproximal end a distal end and a length and a second face located at theproximal end of the second cylinder and oriented transverse to thecentral axis wherein the length of the second cylinder is greater thanone centimeter.

A gastrointestinal device for implanting within a pylorus, a duodenalbulb, and a duodenum of a patient's gastrointestinal tract, the devicecomprising a first expandable portion comprising a hollow tubularbraided structure of wire shaped to include a disk portion configured tobe located on a stomach side of the pylorus; a central cylinder portionhaving a first end, a second end, and a diameter that fits within thepylorus; a second expandable portion comprising a hollow tubular braidedstructure of wire shaped to include a cylinder having a proximal end,and distal end, a length between the proximal end and distal end, and adisk portion to be located on an intestinal side of the pylorus, thesecond expandable portion including a structural element configured toresist circumferential compression; and an intestinal bypass sleevecomprising a sleeve portion, wherein the sleeve portion extends from theduodenal bulb into the duodenum.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a portion of the digestive tract ina human body with a pyloric anchor and sleeve implanted in the pylorus.

FIG. 2 is a cross-sectional view of a portion of the digestive tract ina human body with a pyloric anchor implanted and an intestinal bypasssleeve attached.

FIG. 3 is a cross-sectional view of a portion of the digestive tract ina human body with a pyloric anchor implanted in the pylorus, showing abraided wire structure of the anchor according to some embodiments.

FIG. 4 is a cross-sectional view of a portion of the digestive tract ina human body with a pyloric anchor implanted in the pylorus, showing anoverall structure of the anchor and flanges according to someembodiments.

FIG. 5 shows a pyloric implant from three points of view and illustratesan exemplary embodiment of a structural element having a ringconfiguration.

FIG. 6 shows a pyloric implant from three points of view and illustratesan exemplary embodiment having multiple structural elements having aring configuration.

FIG. 7 shows a pyloric implant from three points of view and illustratesan exemplary embodiment having multiple structural elements having aring configuration.

FIG. 8 shows a pyloric implant from three points of view and illustratesan exemplary embodiment having multiple structural elements having aring configuration.

FIG. 9 shows a pyloric implant from three points of view and illustratesan exemplary embodiment of a structural element according to someconfigurations.

FIG. 10 shows a pyloric implant from three points of view andillustrates an exemplary embodiment of a structural element according tosome configurations.

FIG. 11 shows a pyloric implant from three points of view andillustrates an exemplary embodiment of a structural element according tosome configurations.

FIG. 12 shows an exemplary embodiment of a structural element and apyloric implant with a structural element attached, according to someconfigurations.

FIG. 13 shows an exemplary embodiment of a structural element and apyloric implant with a structural element attached, according to someconfigurations.

FIG. 14 shows an exemplary embodiment of a structural element and apyloric implant with a structural element attached, according to someconfigurations.

FIG. 15 shows an exemplary embodiment of a structural element havingrings and a pyloric implant with a structural element attached,according to some configurations.

FIG. 16 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 17 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 18 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 19 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 20 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 21 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with various structural elementsattached, according to some configurations.

FIG. 22 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 23 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 24 shows an exemplary embodiment of a structural element andvarious views of a pyloric implant with a structural element attached,according to some configurations.

FIG. 25 is a perspective view of an exemplary pyloric implant with aproximal structural element and a distal structural element, accordingto some embodiments.

FIG. 26 is a side view of an exemplary pyloric implant with a proximalstructural element and a distal structural element, according to someembodiments.

FIG. 27 is an axial view of an exemplary pyloric implant with a proximalstructural element and a distal structural element, as viewed from thedistal end, according to some embodiments.

FIG. 28 is an axial view of an exemplary pyloric implant with a proximalstructural element and a distal structural element, as viewed from theproximal end, according to some embodiments.

FIG. 29 is an axial view of an exemplary structural element that can beused on a flange of an implant, according to some embodiments.

FIGS. 30A and 30B are a side view of an exemplary structural elementthat can be used on a flange of an implant, according to someembodiments.

FIG. 31 is a side view of an exemplary pyloric implant with a distalstructural element and a proximal structural element in a contractedconfiguration, according to some embodiments.

FIG. 32 is a side view of an exemplary pyloric implant, according tosome embodiments.

FIG. 33 is a perspective view of an exemplary implant having anintestinal bypass sleeve, according to some embodiments.

FIG. 34 is a perspective view of an exemplary implant having anintestinal bypass sleeve, according to some embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

According to some embodiments, the present disclosure includes anapparatus and method to place and/or anchor a gastrointestinal devicewithin the pyloric antrum, pylorus, duodenum and jejunum. Thegastrointestinal device disclosed herein may be implanted by insertingit endoscopically (when the device is loaded into a delivery catheter)through the mouth, throat, stomach and intestines. The gastrointestinaldevice may include an anchor that can be implanted and remain within apylorus. The gastrointestinal device may also include an expandableanchor having a flexible thin-walled sleeve attached to the distal endof the anchor. In some embodiments, secondary anchors may also anchorother portions of the thin-walled sleeve.

The instant disclosure may include an expandable anchor that can also beused to hold open the pylorus and may help to reduce the symptoms ofgastroparesis by allowing the stomach contents to exit the stomacheasier through the pylorus into the duodenum. The instant disclosure mayinclude additional structure, such as an expandable anchor having ashort bypass sleeve or no bypass sleeve. In some embodiments, an activepumping means may also be attached to the expandable anchor to activelypump the stomach contents from the pyloric antrum into the duodenum.

The present disclosure is an exemplary version of the apparatus andmethods described in U.S. Pat. No. 9,044,300, entitled “GastrointestinalProstheses,” granted Jun. 2, 2015, which is incorporated herein byreference. The instant disclosure provides improvements on theperformance of previously designed implants. Certain design improvementsare generally intended to improve the anchoring performance of theimplant and decrease the likelihood that the implant can migrate inresponse to physiological changes of the body. Additional improvementsdisclosed herein minimize the likelihood that the sleeve portion of theimplant becomes everted or obstructed.

FIG. 1 is a cross-sectional view of a portion of a human digestive track10, showing an embodiment of a device 100 that may be implanted betweenthe stomach 16 and the small intestine 18. As shown in FIG. 1, thedevice 100 may be implanted generally within the pylorus 20 with atleast a section configured to remain within the pyloric antrum 22. Thedevice 100 may be configured to be implanted with portions of the device100 held within the stomach 16, the pylorus 20, and the small intestine18. The device 100 may be endoscopically implanted within the pylorus 20in a compressed configuration. After implantation, the device 100 may bereleased and assume an expanded configuration. Once in the expandedconfiguration, the device 100 generally anchors itself to remain with atleast a portion of the device 100 within the pylorus 20.

FIG. 2 is a cross-sectional view of a portion of the digestive tract ina human body showing the pyloric antrum 22, pylorus 20, duodenum 24, andduodenal bulb 26. FIG. 2 also shows the device 100 implanted between thestomach 16 and small intestine 18. As shown in FIG. 2, the device 100may generally comprise an expandable portion 110 that holds or anchorsthe device 100 in place, and a sleeve portion 120.

The device 100 as a whole may be alternatively referred to as animplant, an implantable device, a gastrointestinal device, agastrointestinal implant, or a pyloric implant. The portion of thedevice 100 that is able to expand and hold the device 100 in place afterimplantation may be referred to as the anchor, the anchoring portion,the holder, or the holding portion. The sleeve 120 portion of the device100 that is shown within the small intestine 18 may be alternativelyreferred to as the sleeve, the intestinal sleeve, the bypass sleeve, theintestinal bypass sleeve, the liner, or the bypass liner. For example,the device 100 may include an intestinal bypass sleeve 120 that isdesigned to be implanted in the duodenum 26 from the pylorus 20 to theligament of treitz (not shown). As shown in FIG. 2, the sleeve 120 isgenerally held in place in the small intestine 18 by the anchoringportion 110 of the device that anchors within or on the pylorus 20.

According to various embodiments, the sleeve 120, the anchor 110, orboth are further coupled at or within the pylorus 20 using one or moreof the techniques described in either of U.S. Pat. No. 8,211,186 or U.S.Pat. No. 8,282,598 filed Jul. 9, 2010, entitled “External AnchoringConfiguration for Modular Gastrointestinal Prostheses,” both of whichare incorporated herein by reference. According to various embodimentsof the invention, the sleeve 120 may be configured to be coupled to theanchor 110, using one or more of the configurations disclosed in U.S.Pat. No. 8,702,641, filed Jan. 7, 2011, entitled “GastrointestinalProstheses Having Partial Bypass Configurations,” which is incorporatedherein by reference.

FIG. 3 illustrates an exemplary embodiment of the anchor 110. The anchor110 has an overall cylindrical shape with a length and a width. In someembodiments, the anchor 110 has an overall cylindrical shape, with acentral axis oriented along a longitudinal direction. The anchor 110 hasa proximal portion 130, a distal portion 132, and a neck portion 134.

In some embodiments, the proximal portion 130 is shaped in a circular ordisk shape. In some embodiments, the proximal portion 130 is shaped in acircular or disk shape having a lip or rim. The proximal portion 130 mayinterchangeably be referred to as a proximal flange. The lip or rim maydefine a proximal portion proximal end 140 and a proximal portion distalend 142. The lip or rim forming the proximal portion proximal end 140and the proximal portion distal end 142 may define an overallcylindrical or tubular shape. In some embodiments, the proximal portion130 circular or disk shape defines a face or wall 148 also referred toherein as the proximal portion wall 148 or proximal flange wall. Theproximal flange wall 148 may be a disk that is located on the distalside 142 of the proximal flange 130. The proximal flange wall 148 may bea disk or disk shaped and oriented transverse to the central axis. Ingeneral, the proximal end 140 of the proximal portion 130 is open toallow chyme to enter. The distal end 142 of the proximal portion 130 maybe connected to the proximal flange wall 148.

In some embodiments, the neck portion 134 defines a through-lumen 152that allows chyme to flow from the stomach 16 to the small intestine 18.The neck portion 134 may be rigid to hold the pylorus 20 open or it maybe compliant to allow the opening and closure of the through lumen 152with the pylorus 20.

In some embodiments, the distal portion 132 is shaped in a circular ortubular shape. In some embodiments, the distal portion 132 is shaped ina circular, disk, or tubular shape having a lip or rim. The distalportion 132 may interchangeably be referred to as a distal flange. Thelip or rim may define a distal portion proximal end 144 and a distalportion distal end 146. The lip or rim forming the distal portionproximal end 144 and the distal portion distal end 146 may define anoverall cylindrical or tubular shape. In some embodiments, the distalportion 132 circular or disk shape defines a face or wall 150 alsoreferred to herein as the distal portion wall 150 or distal flange wall.The distal flange wall 150 may be located on the proximal side of thedistal flange 132. The distal flange wall 150 may be formed as a disk ordisk shaped that is oriented transverse to the central axis. Theproximal end 144 of the distal portion 132 may be connected to thedistal flange wall 150. In general, the distal portion 132 or distalflange is located in the duodenum and the distal flange 132 has anopening at the distal end 146 that faces the intestine 18.

In some embodiments, the distal flange 132, and the neck portion 134each form a generally cylindrical shape, each with an independentdiameter. For example, the proximal flange 130 has an overallcylindrical shape with an open proximal end 140 having a first diameter,and a distal end 142 having a proximal flange wall 148 that necks downto a diameter of the neck portion 134. The proximal flange wall 148 canbe shaped having an angle with a bias in relation to the central axis.The neck portion 134 comprises a cylinder having a second diameter andextends between the proximal flange 130 and the distal flange 132. Thedistal flange 132 has a generally cylindrical shape and includes thedistal flange wall 150 starting from the neck portion 134 and expandingradially from the central axis. The distal flange 132 has a proximal end144 that is positioned near the pylorus 20, and a distal end 146 thatfaces into the small intestine 18. The anchor can be oriented by acentral axis that is defined as the direction traveling from theproximal flange 130, through the neck portion 134, and continuingthrough the distal flange 132.

The braided wire structure of the implant may be formed into a shape topromote anchoring to the tissue of a patient. For example, the proximalflange wall 148 and distal flange wall 150 can be angled in relation tothe neck portion 134 in order to provide certain spatial relationshipsto the pylorus 20 at particular locations. In some embodiments, both theproximal flange 130 and distal flange 132 are shaped to apply force F tothe proximal and distal face of the pylorus 20, respectively. The effectof this force is intended to keep the implant in place, anchored acrossthe pylorus 20.

The overall length of the anchor 110 can be from about 10.0 mm to about100.0 mm, but varying sized anchors may be formed, depending on apatient's anatomy or anatomical fit. In some embodiments, the anchor 110length may be from about 10.0 mm to about 100 mm, from about 25.0 mm toabout 75.0 mm, from about 40.0 mm to about 60.0 mm, or any length withinthese ranges. An exemplary anchor 110 has been formed that is about 50.0mm long but typical anchors may be in the range of between about 45.0 mmand 55.0 mm. In some embodiments, the diameter of the proximal flange130 can be from about 10.0 mm to about 75.0 mm, or any range in between,for example from about 25.0 mm to about 60.0 mm, and from about 40.0 mmto about 55.0 mm. An exemplary anchor 110 has been formed with thediameter of the proximal flange 130 about 40.0 mm.

In some embodiments, the distal flange 132 is shaped as a cylinder witha generally open distal end 146 and partially restricted proximal end144 connected to the distal flange wall 150. The distal flange 132 maybe formed in an overall cylindrical shape having a diameter. The lengthand diameter of the distal flange 132 can be sized to prevent canting ortilting within a tubular anatomical structure such as the duodenum. Insome embodiments, the diameter of the distal flange 132 may be fromabout 5.00 mm to about 60.0 mm, or any range in between, for examplefrom about 20.0 mm to about 50.0 mm, or from about 30.0 mm to about 40.0mm. For example, the distal flange can have a length of roughly 18.0 mmand a diameter of 35.0 mm, to ensure the structure can remain positionedwithin a tubular anatomic structure such as the duodenal bulb with adiameter of about 40.0 mm. An exemplary anchor 110 has been formed withthe diameter of the distal flange 132 about 35.0 mm in diameter.

As shown in FIG. 3, in some embodiments, the diameter of the distalflange 132 may define a gap or space between the diameter of the distalflange 132 and the duodenum. In some embodiments, a gap or space betweenthe diameter of the distal flange 132 and the duodenum may allow theanchor 110 to rotate or turn in a direction generally perpendicular tothe central axis of the anchor 110 or a longitudinal axis defined by thecenter of the opening of the pylorus. If the anchor 110 is allowed torotate after it is implanted in a patient, the distal flange 132 oranchor 110 or both may undergo unwanted movement or deflection and insome cases become dislodged. Rotation or turning of the anchor 110 orthe distal flange 132 may be inhibited by providing a distal flange 132having a suitable length and diameter. A distal flange 132 length mayallow the distal flange 132 to contact the duodenum and prevent furtherrotation before the distal flange 132 or anchor 110 become deflected ordislodged. The length of the distal flange 132 may determine the degreeof rotation the anchor 110 may undergo before contacting the duodenum.In some embodiments, the length and the diameter of the distal flange132 are sized such that upon rotation or canting of the anchor 110 awayfrom the longitudinal axis, the distal end 146 of the distal flange 132will make contact with the intestinal wall and therefore will resistmigration of the anchor 110 within a patient. It has been found that asuitable distal flange 132 length that may inhibit unwanted rotation orcanting or longitudinal deflection may be from about 10.0 mm to about50.0 mm or any length in between. In some embodiments, the distal flange132 may have a length that is sized in relation to the width of thedistal flange 132.

In some embodiments, the distal flange 132 may have a length that issized in relation to the length of the proximal flange 130. For example,the length of the distal flange 132 may be the same length as theproximal flange 130. In some embodiments, the length of the distalflange 132 may be multiples of the length of the proximal flange 130.For example, the distal flange 132 may be one and a half, two times,three times, or greater, the length of the proximal flange 130.

In some embodiments, the diameter of the neck portion 134 may be fromabout 2.0 mm to about 30.0 mm, or any range in between. for example fromabout 5.00 mm to about 30.0 mm, and from about 10.0 mm to about 20.0 mm.An exemplary anchor 110 has been formed with the diameter of the neckportion 134 about 15.0 mm.

In some embodiments, the length of the neck portion 134 may beapproximately the width of a patient's pylorus. In some embodiments, thelength of the neck portion 134 may be longer than the width of apatient's pylorus to provide a gap between the proximal flange wall 148and the distal flange wall 150 and the pylorus 20. In some embodiments,the neck portion 134 may be sized to allow the proximal flange wall 148and the distal flange wall 150 to contact the pylorus 20. In someembodiments, the anchor 110 is compressible in diameter and the overalldiameter can be reduced to about 5.00 to 10.0 mm in diameter typicallyto allow the anchor 110 to be loaded into a catheter (described furtherbelow).

As shown in FIG. 4, in some embodiments, the anchor 110 is formed from ahollow tubular braided structure 160 of wire. The diameter of the wirethat is used to form the braided structure 160 can range from about0.001 inch to about 0.014 inch, from about 0.004 inch to about 0.011inch, from about 0.006 inch to about 0.009 or any diameter within thisrange such as 0.008 inch The braided structure 160 of wire is weaved toform a mesh structure 162. The mesh structure 162 may be shaped to formthe various elements of the anchor 110. The mesh structure 162 is formedinto a shape with a proximal flange 130, a neck portion 134, and adistal flange 132.

The braided structure may be weaved to form a mesh structure 162, andthe mesh can be formed into various components. For example, the meshstructure 162 may be formed into disks or cylinders of the various partsof the anchor 110. Suitably sized cylinders may be formed from the meshstructure and may have a diameter from about 10 mm in diameter to about70 mm in diameter, from about 14 mm to about 50 mm in diameter, and anydiameter in between. In some embodiments, a braided structure 160 ofdifferent diameters may be used at various locations of the anchor 110.For example, an anchor 110 may be created using a braided structure 160having a diameter of about 14 mm for the neck portion 134, a braidedstructure 160 having a diameter of about 34 mm for the distal flange132, and a braided structure 160 having a diameter of about 40 mm forthe proximal flange 130. In exemplary embodiments, the number of wireends in the braided structure 160 is 96 ends, but it can range from 4ends to 256 ends. The wire can be formed from a metal such as Nitinol,MP35N, L605, Elgiloy, stainless steel or from a plastic such as Pet,Peek or Delrin or other suitable material.

The anchor 110 can be covered on the outside and/or inside side with apolymer membrane covering. The membrane covering the anchor 110 may bemade from a thin-walled polymer material such as silicone, polyurethane,polytetrafluoroethylene, fluorinated ethylene propylene, polyethylene,expanded poly tetrafluoroethylene (ePTFE) or other suitable material. Insome embodiments, the wall thickness of the membrane covering the anchor110 may be in the range of 0.001 inch to 0.030 inch thick. The membranemay be made by extrusion, dip coating from a liquid solution, powdercoated from fine particles of polymer or paste extruded and thenstretched as is the case with ePTFE. The anchor membrane may also be cutfrom a flat sheet of material such as ePTFE and then bonded or sewn intoa disk shape or spherical shaped structure and then attached to theanchor 110 by sewing or gluing with a polymer such as FEP.

In some embodiments, the anchor 110 also incorporates a structuralelement contained within the overall structure. Various configurationsof the structural element can be found in the following FIGS. 5 through24.

FIG. 5 shows three views of the implant described in FIG. 3 and isintended to highlight an exemplary embodiment of an anchor 110 and astructural element 170. In some embodiments, a structural element 170 islocated in any of the proximal flange 130, the distal flange 132, orboth. In an exemplary embodiment, a structural element 170 is located atleast within the distal flange 132. For example, a structural element170 may be located in the distal flange 132, proximate the neck portion134, and may be weaved through the mesh structure 162 to maintain asuitable position. The structural element 170 is typically designed toprovide support to the braided structure and contribute to resistingcompression or deformation of the overall shape of the anchor 110. Thebraided structure 160 alone will compress uniformly in response to acircumferential force and therefore the body may be able to push theimplant from its location across the pylorus, leading to migration. Withthe structural element 170 in place, the implant is more resistant tocompression due to the shape and resistance of the structural element170. The structural element 170 may deform independently from thebraided structure 160 and therefore may provide support in addition toresistance to compression. The structural element 170 may providesupport to the overall length, shape, diameter, or bias of the anchor110.

The structural element 170 can be made from a metal such as Nitinol,MP35N, L605, Elgiloy, stainless steel or from a plastic such as PET,PEEK, or Delrin or other suitable material. In a preferred embodiment,the structural element 170 is made from superelastic Nitinol wire formedinto the particular shape. The wire has a diameter from about 0.010 inchto about 0.030 inch, or from about 0.015 inch to about 0.025 inch, orany diameter in between. In one example, a structural element was formedfrom Nitinol wire having a diameter of about 0.020 inch in diameter. Ifa structural element having a particular rigidity or stiffness isrequired, often the size and material that the stiffening element ismade from can be used to control these properties. As an example,Nitinol wire has been used to form stiffening elements, which have acompressive and expansive strength that is a function of the diameter ofthe wire used to make the stiffening element.

In some embodiments, the various components of the anchor 110, includingthe braided structure 160, the mesh structure 162, the mesh structurewith a membrane, and the structural element 170 provide structuralsupport both individually and in combination. The braided structure 160and mesh structure 162 may contribute support both in a radial andlongitudinal direction. The structural element 170 may enhance theoverall strength and rigidity of the anchor both in the radial andlongitudinal direction. Additionally, the structural element 170 may betailored to provide a bias to the braided structure 160 and meshstructure 162 to allow the anchor to form a particular shape in responseto certain forces. For example, the structural element 170 may addstiffness to the anchor 110 and allow it to maintain an effectivecircumference. The structural element 170 may provide a compressionlimit to the anchor 110. The structural element 170 may add longitudinalstability. The structural element 170 may inhibit the anchor 110 frommoving through the pylorus.

As shown in FIG. 5, in some embodiments, the structural element 170 iscomprised in the shape of a ring. The diameter of a ring formed tocreate a structural element may be sized to form a suitable fit for usein an anchor 110, or at various locations on an anchor. For example, thediameter of a ring may be from about 20 mm to about 50 mm, from about 25mm to about 45 mm, from about 30 mm to about 40 mm, and any diameterwithin this range. In one example, a ring was formed having a diameterof about 35 mm.

FIG. 6 describes an alternative embodiment to the implant shown in FIG.5. In some embodiment, the anchor 110 incorporates a proximal structuralelement 172. The proximal structural element 172 is located at theproximal wall or face 148 of the proximal flange 130, nearest to theneck portion 134 of the anchor 110. The function of the proximalstructural element 172 is to resist compression of the overallstructure. The proximal structural element 172 is weaved through themesh structure 162 to secure it to the anchor 110. The proximalstructural 172 element may be made from the same material as thestructural element 170.

FIG. 7 is an alternative embodiment to the implant shown in FIG. 5. Theanchor 110 incorporates two structural elements 174, 176 each of whichare 180 degrees apart, orientated out-of-plane relative to the distalwall or face 150 of the distal flange 132. This configuration providesan additional option not available in the design shown in FIG. 5 byenabling the structure to be collapsed into a shape that can be loadedinto a small diameter tube for the purpose of delivering or retrievingthe implant endoscopically in a human. While the structural elements174, 176 can still resist circumferential compression, when thestructure is pulled into a tube, the structural elements 174, 176 willcollapse into an elliptical shape. The structural elements 174, 176included here comprise rings.

FIG. 8 is an additional embodiment to the implant shown in FIG. 7 inwhich the anchor 110 incorporates three structural elements 174, 176,178. In this example, the structural elements 174, 176, 178 compriserings each 120 degrees apart from each of the others, orientatedout-of-plane relative to the wall or face 150 of the distal flange 132.This configuration provides an advantage over the design shown in FIG. 7because it is symmetrical with respect to the distal flange 132 and withrespect to a patient's anatomy. The overall structure can still becollapsed into a shape that can be loaded into a small diameter tube forthe purpose of delivering or retrieving the implant endoscopically in ahuman.

FIG. 9 illustrates an additional embodiment of an alternative structuralelement 190. The anchor 110 incorporates a single alternative structuralelement 190 shaped to provide additional strength to the overallstructure. This configuration provides an advantage over certainembodiments by enabling the structure to be collapsed more easily into ashape that can be loaded into a small diameter tube for the purpose ofdelivering or retrieving the implant endoscopically in a human. Whilethe alternative structural element 190 can still resist circumferentialcompression, when the structure is pulled into a tube, the alternativestructural element 190 will collapse into an elliptical shape. Variousstructural features also enable the anchor 110 containing an alternativestructural element 190 to be collapsed and provide a bias to thedirection of collapse.

FIG. 10 illustrates an additional embodiment of an alternativestructural element 190. The anchor 110 incorporates an alternativestructural element 190 shaped to provide additional strength to theoverall implant structure. This configuration enables the structure tobe collapsed into a shape that can be loaded into a small diameter tubefor the purpose of delivering or retrieving the implant endoscopicallyin a human. While the alternative structural element 190 can stillresist circumferential compression, when the structure is pulled into atube, the alternative structural element 190 will collapse into anelliptical shape. Various structural features also enable the anchor 110containing an alternative structural element 190 to be collapsed andprovide a bias to the direction of collapse.

FIGS. 11 to 20 illustrate various embodiments and shapes of analternative structural element 190. The embodiments shown in FIGS. 11 to20 all have the features of providing additional strength to the overallstructure of the anchor 110 and are collapsible. The illustratedembodiments enable the anchor 110 to be collapsed into a shape that canbe loaded into a small diameter tube for the purpose of delivering orretrieving the implant endoscopically in a human. Various structuralfeatures also enable the anchor 110 containing an alternative structuralelement 190 to be collapsed and provide a bias to the direction ofcollapse.

The anchor 110 illustrated in FIGS. 9 to 24 has the advantage that astructural element 190 has been added to provide structural support tothe anchor 110 in addition to the braided structure 160. To providestructural support and to optimize the expanded configuration of eitherthe proximal 130 flange, the distal flange 132, or both flanges, theorientation of the structural element 190 is arranged to provide any ofa static radial force, a static longitudinal force, or both. As anexample, FIG. 13 contains an embodiment of a structural element 190 thatis capable of providing both radial support and longitudinal support. Asused herein, the term longitudinal support refers to structural supportfor maintaining the anchor 110 in an expanded configuration along adirection parallel to the central axis. As used herein, the term radialsupport refers to support for maintaining the anchor 110 in an expandedconfiguration along a direction perpendicular to the central axis. Oftenthis can be accomplished by having the structural element 190 connectedto the neck portion of the anchor 110 and transverse a flange in aradial direction.

In the structure illustrated in FIG. 13, the structural element 190 isgenerally attached to the anchor 110 at various touch points. The shapeand size of the structural element 190 can be chosen to provide asuitable fit for a particular patient. It may be that certain portionsof an anchor 110 require greater longitudinal support. This can beaccomplished by increasing the size of the structural element 190 in thelongitudinal direction, as illustrated by comparing the structuralelement 190 in FIGS. 11 to 13. For example, in certain embodiments, apatient may need greater support in the longitudinal direction which canbe accomplished by providing a compressive force by the anchor 110 inthe longitudinal direction. Another option is to provide structuralsupport in the longitudinal direction past the end of the distal flange.This may be accomplished by using the embodiment illustrated in FIG. 13.

In some embodiments, the structural element 190 illustrated in FIG. 13may be used, for example, to maintain a sleeve that is attached to theanchor 110 in an open configuration. As an example, a sleeve may beattached to the neck portion of the anchor 110 at the distal wall. Thesleeve may be attached to the structural element 190 at various pointsalong the sleeve as the sleeve extends through the end of the distalflange and continues out in a longitudinal direction. The structuralelement 190 is sized to extend past the end of the distal flange andthus a portion of the structural element 190 can be attached to thesleeve outside the distal flange. In this configuration, the sleeve isheld away from the neck portion at a greater distance and thus thesleeve is prevented from everting or inverting into the neck portion.This embodiment may provide a more versatile arrangement as well whenattaching a wider sleeve in, for example, a patient with a widerintestine, the structural element 190 can also be used to keep thesleeve open to allow food to enter the sleeve easier and continue onthrough the intestine.

FIGS. 21 to 24 illustrate various embodiments and shapes of analternative structural element 190. The embodiments shown in FIGS. 21 to24 all have the features of a structural element 190 providingadditional strength to the overall structure of the anchor 110 and arecollapsible.

In some embodiments, such as those shown in FIGS. 21 to 24, structuralsupport can be provided to both the proximal flange and the distalflange with a single structural element 190 by providing a structuralelement 190 with a particular shape. For example, the structural element190 may be shaped with the structural element 190 contoured through ororiented longitudinal to the neck portion and extending through at leastone flange. The points of attachment on both the neck portion and theflanges are selected to enable compressive and expansive forces to betransferred between the flanges and the neck portion by the structuralelement 190.

In the embodiments illustrated in FIGS. 21 to 24, the structural element190 traverses the neck portion of the anchor. The orientation andlocation of such a structural element 190 enables the structural element190 to maintain the angle of each flange perpendicular to the neckportion. This allows each flange to resist circumferential compressionwhile also preventing each flange from canting. The illustratedembodiments enable the anchor 110 to be collapsed into a shape that canbe loaded into a small diameter tube for the purpose of delivering orretrieving the implant endoscopically in a human. Various structuralfeatures also enable the anchor 110 containing an alternative structuralelement 190 to be collapsed and provide a bias to the direction ofcollapse.

As shown in FIG. 25, in some embodiments, the anchor 110 has a distalstructural element comprised of three rings 193, 194, 196 attached tothe distal flange 132. The distal structural element 193, 194, 196 canbe made from a metal such as Nitinol, MP35N, L605, Elgiloy, stainlesssteel or from a plastic such as PET, PEEK, or Delrin or other suitablematerial. In a preferred embodiment, the distal structural element 193,194, 196 is made from superelastic Nitinol wire formed into theparticular shape. In one example, a structural element was formed fromthree rings of Nitinol wire. If a structural element having a particularrigidity or stiffness is required, often the size and material that thestiffening element is made from can be used to control these properties.Typically, the Nitinol wire that has been used to form stiffeningelements has a compressive and expansive strength that is a function ofthe diameter of the wire used to make the stiffening element.

The distal structural element 193, 194, 196 may be formed of materialhaving a thickness in the range from 0.010 inch to about 0.040 inch, orany range in between such as from about 0.015 inch to about 0.030, fromabout 0.020 inch to about 0.025 inch. In an example embodiment, a distalstructural element 193, 194, 196 comprised a plurality of rings formedfrom material having a thickness of about 0.020 inch, or about 0.51 mm.Generally, each of the three rings that form the distal structuralelement 193, 194, 196 have the same diameter which are in the range offrom 1.0 inch to 2.0 inches, and any range within such as from about 1.2inches to about 1.8 inches, and from about 1.3 inches to about 1.7inches. In an example embodiment, the distal structural element 193,194, 196 comprised material formed into rings each having a diameter ofabout 1.38 inches, or about 35.0 mm.

As shown in FIGS. 25 and 26, the three rings of the distal structuralelement 193, 194, 196 are arranged around the distal flange 132 and areattached to the distal flange 132 by being integrally woven into theflange material. The rings of the distal structural element 193, 194,196 are attached by first weaving the formed wire of the rings thoughthe braided structure of the distal flange 132 and then the wire endsare inserted into a sleeve and crimped or welded. FIG. 26 contains aside view of an example embodiment of the anchor 110, illustrating howeach ring may be arranged with at least a portion of each ring attachedto the distal flange distal end 146 and a portion attached to the distalflange distal wall 150. In still further embodiments, each ring may beattached with at least a portion of each ring closer to the distalflange proximal end 144 and a portion attached to the distal flangedistal wall 150.

To provide structural support and to optimize the expansive force of theflanges, the orientation of the structural element or rings are arrangedto provide any of a static radial force, a static longitudinal force orboth. Often this requires the structural element to receive radialsupport from the neck portion or the wall of the anchor. In someembodiments, such as those shown in FIGS. 21 to 24, this is accomplishedby providing a structural element with a particular shape. In someembodiments, the design of the structural element may incorporate aplurality of rings. The orientation of the rings relative to the wall orface of the flange can be designed to provide suitable static structure.This can be accomplished by placing the rings out-of-plane with theflange wall. In a structure incorporating rings for the structuralelement, the rings are generally attached to the implant at about fourlocations. The attachment locations are evenly spaced around the ringand enable the compressive and expansive forces to be transferredbetween the flanges and the structural element evenly.

As shown in FIGS. 25 and 26, in some embodiments the anchor 110 may havea proximal structural element 172 attached to the proximal flange 130.The proximal structural element 172 may also be referred to as acompression bias spring. The proximal structural element 172 may beconstructed as a substantially circular frame having nodes 204. Theproximal structural element 172 may be constructed from the samematerial that forms the distal structural element 193, 194, 196. Theproximal structural element 172 may also provide structural support tothe proximal flange 130. For example, the proximal structural element172 generally has an overall frame that is compressible, yet also isrigid. The rigid proximal structural element 172 tends to impartadditional strength to the proximal flange 130 and aids in keeping theproximal end 140 of the proximal flange 130 open. The proximalstructural element 172 can be shaped to bias the collapse of thediameter of the anchor 110 for removal from a patient and for loadingthe device onto a delivery catheter for delivery within a patient.

As shown in FIGS. 25 and 26 in some embodiments, the anchor 110 mayinclude a drawstring 192. The drawstring may be attached to the proximalflange 130. The drawstring 192 typically can be attached to the proximalflange 130 by weaving the drawstring 192 through the material of theproximal flange 130. As shown in FIG. 26, the drawstring may be weavedthrough the material of the proximal flange and have a portion of thedrawstring forming a drawstring loop 205. For example, the drawstring192 may be constructed from a string or suture that is weaved throughalternating cells in the braided wire structure of the anchor 110. Thedraw string loop 205 allows the drawstring 192 to be attached to aretraction tool, for example by a hook or a clamp. In some embodiments,the drawstring 192 is simply a suture that is weaved through theproximal flange 130. The drawstring may be separate from the proximalstructural element 172. The drawstring may be constructed from any rangeof suture material and may comprise a thin wire or cable. The drawstring192 can be used to elastically contract the anchor 110 by connecting atleast one loop 205 to a removal device (not shown) and by drawing into asheath, for example a catheter. In some embodiments, the drawstring 192allows the proximal flange 130 to collapse to the diameter of the neckportion 134.

FIG. 27 shows the anchor 110 from an axial perspective looking down thelongitudinal direction from the distal end 146 of the distal flange 132.In some embodiments, the distal flange 132 has an outer circumference198, defined by the outer most edge of the proximal end 144 or distalend 146 of the distal flange 132, and an inner circumference 199 definedby the location where the distal flange distal wall 150 meets the neckportion 134. In some embodiments, the inner circumference 199 of thedistal flange is the same circumference as a circumference of the neckportion 134. As illustrated in FIG. 27, the distal structural element193, 194, 196 may be formed by placing three rings at equal distancesfrom each other around the distal flange 132 to provide pressure outwardfrom an inner circumference 199, for example starting from the distalflange distal wall 150, and push outward against the outer circumference198 of the distal flange 132.

FIG. 28 illustrates the proximal structural element 172 and thedrawstring 192 within the proximal flange 130 of the anchor 110 asviewed from an axial perspective looking down the longitudinal directionfrom the proximal end 140 of the proximal flange 130. In someembodiments, the proximal flange 130 has an outer circumference 208,defined by the outer most edge of the proximal end 140 or distal end 142of the proximal flange 130, and an inner circumference 209 defined bythe location where the proximal flange proximal wall 148 meets the neckportion 134 (shown in FIG. 26). In some embodiments, the innercircumference 209 of the proximal flange 130 is the same as acircumference of the neck portion 134.

FIG. 29 illustrates an embodiment of the proximal structural element 172without the anchor, to illustrate an overall shape and structure. FIG.29 shows the proximal structural element 172 as viewed from an axialperspective looking down the longitudinal direction and shows theproximal structural element 172 having a main body 212 that issubstantially circular and having a diameter 214. The proximalstructural element diameter 214 may be in the range of from 1.0 inch to2.0 inches, and any range in between such as from about 1.3 inches toabout 1.8 inches, or from about 1.5 inches to about 1.7 inches. In anexample embodiment, the proximal structural element main body 212comprised a ring having a diameter of about 1.57 inches, or about 40.0mm.

The proximal structural element 172 may be formed of material having athickness in the range from 0.015 inch to about 0.045 inch, or any rangewithin such as from about 0.020 inch to about 0.035 inch, from about0.025 inch to about 0.030 inch. In an example embodiment, a proximalstructural element 172 was formed from material having a thickness ofabout 0.025 inch, or about 0.64 mm.

In some embodiments, attached to the main body 212 of the proximalstructural element 172 is a plurality of nodes 204. As shown in FIGS.30A and 30B, when viewed from the side, the proximal structural elementmain body 212 has an overall planar structure, with the nodes 204extending from the plane of the main body 212. The nodes may be at anangle 214 to the plane of the main body 212, for example the nodes 204may be formed to extend at a 60 degree angle from the main body 212. Thenodes 204 may each have an outer loop 213 and an inner curve 215. Theouter loop 213 allows a bias for the proximal structural element 172 tocollapse radially in response to a compressive force. This action can bedesirable for removal of the anchor from a patient and for loading theimplant onto a delivery catheter for delivery within a patient.Additionally, the angle 214 helps to collapse the anchor in a uniformmanner when the drawstring is pulled. The angle 214 of each node 204allows for evenly distributed tension to be imparted to the main body212 without forming a pinch point. The angle 214 also forms a shape thatallows the anchor a bias toward a retracted configuration when tensionis placed on the drawstring 172.

In some embodiments, the anchor 110 may be may be configured to collapseinto a narrower size. For example, the anchor 110 may be collapsed intoa narrower diameter for placement or removal from a patient. FIG. 31shows the proximal flange 130 of the anchor 110 in the collapsed stage.In some embodiments the anchor can be collapsed by pulling thedrawstring. The drawstring node 205 may be pulled away from the anchor110, collapsing the proximal structural element 172. FIG. 31 shows theproximal flange 130 in a collapsed stage after the drawstring 192 hasbeen pulled.

As shown in FIG. 32, in some embodiments, the proximal flange wall 148and the distal flange wall 150 may be constructed with a bias inrelation to the central axis. The structural element 170 may also beconfigured to impart a bias on the distal flange wall 150. The proximalstructural element, (not shown) may also impart a similar bias on theproximal flange wall 148. For example, the structural element 170 may beconfigured to impart a bias against the distal flange wall 150 in theproximal direction. For example, the distal structural element 170 maybe configured to impart a bias against the distal flange wall 150 in theproximal direction. In other words, in some embodiments, the proximalflange wall 148 and the distal flange wall 150 may not be a completelyflat configuration, but instead may have an angle, curve, or slope. Asalso shown in FIG. 32, the neck portion of the anchor has a length 216.In some embodiments, because of the slope, curve, or angle, of theproximal flange wall 148 and distal flange wall 150 the distance 218between the outer circumference (208 in FIG. 28) of the proximal flangewall 148 and the outer circumference (198 in FIG. 27) of the distalflange wall 150 may be less than the length of the neck portion 216. Asa result, the proximal flange wall 148 has a proximal gap 200 and thedistal flange wall has a distal gap 202. The proximal gap 200 is definedby the difference in the longitudinal location of the proximal flangewall 148 at the outer circumference (208 in FIG. 28) and the innercircumference (209 in FIG. 28). The distal gap 202 is defined by thedifference in the longitudinal location of the distal flange wall 150 atthe outer circumference (198 in FIG. 27) and the inner circumference(199 in FIG. 27).

FIGS. 33 and 34 show an exemplary sleeve 120 that may be used inconjunction with an anchor. As shown previously in FIG. 2, the sleeve120 may be attached to the anchor 110 and be placed within the smallintestine 18. In various exemplary embodiments, the sleeve 120 isintegrally formed with or coupled to the anchor 110. According to someembodiments, the sleeve 120 is removably or releasably coupled to theanchor 110.

As shown in FIG. 34, an overall schematic of a sleeve according to someembodiments includes a mouth 220, a sleeve body 222, and a neck 224 Thesleeve body 222 diameter is generally sized to match the diameter of thehuman small intestine. The diameter decreases at the neck 224 to beconsistent with the inner diameter of the anchor. This change indiameter also helps to prevent sleeve eversion in which the sleeve foldsback into itself in response to an increase in pressure on the outsideof the sleeve. According to various embodiments, the sleeve body has athickness of between about 0.001 and about 0.015 inches. The sleeve neck224 is intended to be thicker than the sleeve body 222, for example0.005 inches versus 0.001 inches thick, to provide a second mechanism toprevent sleeve eversion. When the sleeve is subjected to an externalpressure, the thicker neck 224 collapses and does not fold back onitself. This mechanism essentially creates a duck-bill valve.

The sleeve 120 can vary in length from 1.0-2.0 inches in length up toseveral feet. In some embodiments, the sleeve 120 bypasses the length ofthe duodenum up to the ligament of treitz. While various embodimentsdisclosed herein describe the intestinal bypass sleeve 120 as extendinginto the duodenum, in all such embodiments, it is also contemplated thatthe intestinal bypass sleeve 120 has a length sufficient to allow it toextend partially or fully into the jejunum. Often the length of thesleeve is dictated by the required mechanism of action. It has beenshown that an effective sleeve length is one that allows it to reach theproximal jejunum; this location corresponds to the location of theligament of Trietz. The length of the sleeve is determined based on thedesired clinical outcome. Recent scientific research has indicated thata sleeve roughly 2 feet in length is sufficient to modify the transportand absorption of food and organ secretions within the small intestine,leading to remission of type 2 diabetes.

The intestinal bypass sleeve 120 may be made from a thin-walled polymermaterial such as silicone, polyurethane, polytetrafluoroethylene,fluorinated ethylene propylene, polyethylene, expandedpolytetrafluoroethylene (ePTFE) or other suitable material. In exemplaryembodiments, the wall thickness of the intestinal bypass sleeve 120 maybe between 0.0006 inch and 0.010 inch thick. The intestinal bypasssleeve 120 may be made by extrusion, into a tubular form or a lay flattubing, dip coated from a liquid solution, powder coated from fineparticles of polymer or paste extruded and then stretched as is the casewith ePTFE.

The gastrointestinal device thus described comprises an anchorconfigured to be implanted and remain within a pylorus of a patient. Thegastrointestinal device may comprise an anchor having a flexiblethin-walled sleeve attached to the distal end of the anchor. In someembodiments, secondary anchors may also anchor other portions of thethin-walled sleeve. The anchor may be placed within a pylorus of apatient to assist in opening a pylorus of the patient. The sleeve may beplaced within the intestine of the patient and held in place by theanchor. The device thus described may function as follows.

As a person ingests food, the food enters the mouth, is chewed, and thenproceeds down the esophagus and into the stomach. The food mixes withenzymes in the mouth and in the stomach. The stomach converts the foodto a semi-fluid substance called chyme. The chyme enters the pyloricantrum and exits the stomach through the pylorus. The pylorus (orpyloric sphincter) is a band of muscle that functions to adjust thediameter of the pyloric orifice, which in turn effects the rate at whichchyme exits the stomach. The pylorus (or phyloric sphincter or pyloricwall) also has a width (or thickness), which is the distance that thepylorus extends between the stomach and the duodenum.

A gastrointestinal implant placed within the pylorus of a patent can beemployed to control the opening and closing of the pylorus to controlthe flow rate of chyme from the stomach to the intestine of the patient.An exemplary gastrointestinal implant has been formed that can assumeboth an expanded and contracted configuration. In an exemplaryconfiguration, the implant has a neck portion that allows chyme to flowfrom the stomach to the intestine of a patient. The width of the neckportion can be designed to control the flow rate of chyme from thestomach to the intestine. The flow rate of chyme can optionally bemodified depending on the suitable blood glucose levels of the patient.

The gastrointestinal implant may be held in place within a pylorus of apatient by using an anchor. The anchor comprises a proximal flange and adistal flange connected to the neck portion to anchor the neck portionin place. The proximal flange is configured to remain on the stomachside of a patient's pylorus and the distal flange is configured toremain on the intestinal side of a patient's pylorus. The widths of theproximal flange and distal flange in the expanded configuration arewider than the maximum diameter of the pylorus.

The length of the neck portion can be configured to provide an optimumfit within the pylorus of a patient while preventing the neck portionfrom agitating the tissue of the pylorus. It has been discovered that anoptimum length of the neck portion reduces agitation of the tissue ofthe pylorus by the anchor by reducing contact between the proximal anddistal flanges of the anchor and the pyloric wall. By creating the neckportion to be longer than the width of the pyloric wall, the proximalflange and distal flange are arranged such that they have minimalcontact with the pylorus as the pylorus opens and closes. Additionallyor alternatively, the shape of the proximal flange and distal flange canbe formed to include a bias that reduces contact with the pylorus as thepylorus opens and closes. For example, the proximal flange and distalflange may be formed to provide a space between the proximal flange anddistal flange and the pylorus.

The anchor may be formed from material having a hollow tubular braidedstructure that can assume a collapsed configuration for placement withinand removal from a patient's digestive system. The hollow tubularbraided structure also can assume an expanded configuration for suitableplacement within a patient's digestive track. The anchor may include astructural element that provides additional structural support to theanchor and keeps the anchor in an expanded configuration yet also allowsthe anchor to be compressed for ease of placement within and extractionfrom a patient. For example, a structural element can be placed withinthe distal flange to provide structural support in the radial directionand thus prevent the distal flange from reverting into the stomach of apatient. Additionally or alternatively, a drawstring may be placedwithin the proximal flange to provide structural support in the radialdirection and prevent the proximal flange from traveling into theintestine of a patient. Both the structural elements can be configuredto be compressed into a collapsed configuration to allow the anchor tobe placed within and removed from within a patient's digestive track.The neck portion of the anchor can be tailored to span the pylorus, andmay be tailored to fit various patients of various dimensions.Additionally, the length of the neck portion can be tailored to extendpast the pylorus to reduce a compressive force exerted by the flangesonto the pylorus. For example, the length of the neck portion can bedesigned to sit within the patient's anatomy without continuous contactwith the walls of the duodenal bulb and pyloric antrum. The diameter ofthe neck portion can also be sized to allow food to pass from apatient's stomach to intestine yet remain narrow enough to prevent itfrom propping open the pylorus.

The small intestine is about 21 feet long in adults. The small intestineis comprised of three sections: the duodenum, jejunum, and ileum. Theduodenum is the first portion of the small intestine and is typically10.0-12.0 inches long. The duodenum is comprised of four sections: thesuperior, descending, horizontal and ascending. The duodenum ends at theligament of treitz. The duodenal bulb is the portion of the duodenumwhich is closest to the stomach. Suitably designed sleeves can be sizedwherein the length of the sleeve determines at what point the chyme isallowed to contact the intestine. The design and length of the sleevealso determines at what point food that is traveling through the sleevecomes into contact with digestive juices.

The gastrointestinal implant described here in can be placed within apatient's digestive track by inserting an endoscope through the mouth,esophagus and stomach to the pylorus. An over-the-wire sizing balloon isinserted through the working channel of the endoscope over a guidewireand is advanced across the pyloric opening. The balloon is inflated withsaline or contrast media to a low pressure to open the pylorus andduodenum and allow measurement of the lumen diameter of the pyloricantrum, pylorus and duodenal bulb.

In some embodiments, blood glucose levels can be measured by a glucosesensor and the insulin infusion rates and optimum chyme flow rates canbe set by the diameter of the neck portion. Currently diabetic patientsmonitor blood glucose levels and then based on their insulin levelsinject themselves with insulin either with a syringe or with an infusionpump. Gastric emptying rates vary depending upon the composition of thefood eaten. Sugars pass quickly from the stomach into the smallintestine and protein and fats move from the stomach into the smallintestine more slowly. Blood sugar control can be difficult to manage ifthe flow rate of chyme from the stomach to the small intestine isunpredictable and in the case of patients with gastroparesis the chymeflow rate can be very slow to zero. The disclosure herein described willallow for a tighter glucose level control by allowing more precisecontrol of the flow rate of chyme into small intestine and modulatingthe flow rate of chyme base on blood glucose levels and insulin infusionrate.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. For example, while the embodiments described above refer toparticular features, the scope of this invention also includesembodiments having different combinations of features and embodimentsthat do not include all of the above described features.

What is claimed is:
 1. A gastrointestinal implant for use within apylorus, a duodenal bulb, and a duodenum of a patient, the implanthaving an expanded configuration and a contracted configuration andcomprising: a proximal portion comprising a hollow tubular braidedstructure of wire shaped to form a cylinder having a proximal end, adistal end, and a proximal wall extending radially inward from theproximal portion distal end, wherein the proximal wall has an outercircumference and an inner circumference and is configured with a firstbias such that the inner circumference is located closer to the proximalportion proximal end than the proximal portion outer circumference; aneck portion comprising a cylinder having a proximal end and a distalend and extending distally from the inner circumference of the proximalportion, the neck portion having a length greater than a width of apylorus; a distal portion comprising a hollow tubular braided structureof wire shaped to form a cylinder extending distally from the neckportion and having a proximal end, a distal end, an outer wall extendingbetween the proximal end and distal end, and a distal wall extendingradially inward from the distal portion proximal end, wherein the distalwall has an outer circumference and an inner circumference and isconfigured with a second bias such that the inner circumference islocated closer to the distal portion distal end than the distal portionouter circumference; and a structural element including a plurality ofrings attached to the hollow tubular braided structure, wherein eachring of the plurality of rings has at least a first section coupled tothe distal portion distal wall and at least a second section coupled tothe distal portion outer wall, and wherein each ring of the plurality ofrings is oriented in a plane, and wherein the plane of each ringintersects the plane of each of the other rings between the firstsection of each ring and the second section of each ring, the structuralelement configured to resist circumferential compression along a portionof the outer wall.
 2. The gastrointestinal implant of claim 1, whereinupon implantation within a patient's pylorus the proximal wall firstbias defines a gap between the proximal wall inner circumference and thepatient's pylorus.
 3. The gastrointestinal implant of claim 1, whereinupon implantation within a patient's pylorus the distal wall second biasdefines a gap between the distal wall inner circumference and thepatient's pylorus.
 4. The gastrointestinal implant of claim 1, whereinthe structural element includes at least three rings, wherein each ringis attached along a circumference of the outer wall at a location about120 degrees apart from each of the other rings.
 5. The gastrointestinalimplant of claim 4, wherein the structural element comprises a shapethat consists of a round shape, a rectangular shape, a square shape oran elliptical shape.
 6. The gastrointestinal implant of claim 1, whereinthe proximal portion includes a drawstring.
 7. The gastrointestinalimplant of claim 1, wherein the proximal portion includes a structuralelement comprising a substantially circular main body and a plurality ofloops extending from the main body in the proximal direction.
 8. Agastrointestinal device for implanting within a pylorus, a duodenalbulb, and a duodenum of a patient's gastrointestinal tract, the devicehaving a central axis and comprising: a first expandable portioncomprising a hollow tubular braided structure of wire and having a firstcylinder extending parallel to the central axis, the first cylinderhaving a proximal end, a distal end, and a length; and a first facelocated at the distal end of the first cylinder and oriented transverseto the central axis; a neck portion extending from the first face of thefirst expandable portion parallel to the central axis, the neck portionhaving a first end, a second end, a wall extending between the first endand second end, and a diameter sized to fit within a pylorus; and asecond expandable portion comprising a hollow tubular braided structureof wire and having a second cylinder extending parallel to the centralaxis, the second cylinder having a proximal end, a distal end, and alength; a second face located at the proximal end of the second cylinderand oriented transverse to the central axis; and a structural elementcoupled to the second face and the length of the second cylinder, thestructural element including at least three rings, wherein each of thethree rings is oriented in a plane and wherein the plane of each ringintersects the plane of each of the other two rings; wherein the lengthof the second cylinder is greater than one centimeter.
 9. Thegastrointestinal device of claim 8, wherein the structural elementcomprises a plurality of circular rings arranged to provide structuralsupport radially between the second face and the second cylinder. 10.The gastrointestinal device of claim 8, wherein the structural elementis configured to deform independent of the hollow tubular braidedstructure in response to a compressive force.
 11. The gastrointestinaldevice of claim 8, wherein the neck portion is configured to fit withinthe pylorus and has a through lumen that allows chyme to flow from apatient's stomach to the duodenum.
 12. The gastrointestinal device ofclaim 10, wherein the neck portion is compliant enough to allow openingand closure of the through lumen within the pylorus.
 13. Thegastrointestinal device of claim 8, wherein the neck portion is rigidenough to hold the pylorus open.
 14. The gastrointestinal device ofclaim 8, wherein the second face is oriented transverse to the centralaxis at an angle less than 90 degrees.
 15. The gastrointestinal deviceof claim 8, wherein the length of the second cylinder is sized toprevent rotation of the gastrointestinal device within the duodenalbulb.
 16. The gastrointestinal device of claim 8, wherein the length ofthe second cylinder is from about 1.0 cm to about 10.0 cm.
 17. Thegastrointestinal device of claim 8, wherein the first face is orientedtransverse to the central axis at an angle less than 90 degrees.
 18. Agastrointestinal device for implanting within a pylorus, a duodenalbulb, and a duodenum of a patient's gastrointestinal tract, the devicecomprising: a first expandable portion comprising a hollow tubularbraided structure of wire shaped to include a disk portion configured tobe located on a stomach side of the pylorus, the first expandableportion including a first structural element configured to resist radialcompression of the first expandable portion and having a ring thatincludes at least one node configured to bias the ring into a collapsedconfiguration upon application of a radial force on the first expandableportion; a central cylinder portion having a first end, a second end,and a diameter that fits within the pylorus; a second expandable portioncomprising a hollow tubular braided structure of wire shaped to includea cylinder having a proximal end, and distal end, a length between theproximal end and distal end, and a disk portion to be located on anintestinal side of the pylorus, the second expandable portion includinga second structural element configured to resist circumferentialcompression, wherein the second structural element includes a pluralityof rings attached to the hollow tubular braided structure, each ring ofthe plurality of rings having at least a first section coupled to thedisk portion of the second expandable portion and at least a secondsection coupled to the length of the second expandable portion, andwherein each ring of the plurality of rings is oriented in a plane, andwherein the plane of each ring of the plurality of rings intersects theplane of each of the other rings between the first section of each ringand the second section of each ring; and an intestinal bypass sleevecomprising a sleeve portion, wherein the sleeve portion is configured toextend from the duodenal bulb into the duodenum.
 19. Thegastrointestinal device of claim 18, wherein the second structuralelement comprises a circular ring.
 20. The gastrointestinal device ofclaim 18, wherein the second structural element comprises a plurality ofsubstantially circular rings.
 21. The gastrointestinal device of claim18, further comprising a drawstring attached to the first expandableportion.
 22. The gastrointestinal device of claim 18, further comprisinga drawstring attached to the first expandable portion and configured tocollapse the first expandable portion.